Fuel injection valve



July 24 1956 E. J. KoRDA 2,756,107

FUEL INJECTION VALVE Filed May 16, l1952 5 Sheets-Sheet 1 BHgeeJ dla ATTORN EY July 24, 1956 E. J. KoRDA 2,756,107

FUEL INJECTION VALVE Filed May 16, 195.?. 3 Sheets-Sheet 2 INLET PRESSURE RATE OF FLOW INVENTOR Eugene Jjfordcz July 24, 1956 E, J, KQRDA 2,756,107

FUEL INJECTION VALVE Filed May 16, 1952 3 Sheets-Sheet 3 VII/l FIG. 13

INVENTOR ,gzgezze J/Gnrda ATTORNEY United States Patent@ FUEL INJECTION VALVE lEugene I. Korda, New York, N. Y. Application May I1,6, 1952, Serial Nth-288,110 3 Claims. (Cl. 299-133) The present invention relates to fuel injection valves for internal `cornbustionrengines and moreparticularly to :those which are variable area-oriiicezinjection nozzles.

The :present invention contemplates `the lprovision of such ea'n injection nozzle which is designed and constructed so that it can be calibrated, that is used to Vrneter vthe fuel'y as well as to atomi-z'efit.

In internal combustion engines, as, fffor example, particularly aircraftv gas turbines, a 'plurality of combustion chambers may be used to drive a single turbine. IFuel for all of thecombustion 'chamberslis drawn from acommon supply and the injection nozzles are relied upon to deliver an equal supplyof-fuelito each'combustion'chamberfand atomizeit vupon delivery "to the chamber.

In'the past, injection'nozzleshaving a lvariable'exit area have been used to spray the .fuel into the combustion chambers. This exit varea wasarranged for the fmost yto increase with the Aincrease Aiti inlet fue] pressure. These 'variable exit-area nozzles Shad the advantage-over 'nozzles having a xed or multiple exit area of providinglanfequivavlent 'spray pattern ata lowermaximum inlet pressure and .over a 1wider range of fuel deliveries or '.ilows.

Suchrprior variable exit area nozzles, however, had .the 'accompanying disadvantage Vof diicultyinfobtaining'from :different nozzles'a 'consistentcalibration In other words, two or more of such heretofore variable exit areanozzles tclid l`notrpass the ysame quantity offue'l .fromthe `common supply lineiin a given periodlofl time 4to'each combustion chamber.

In, for example, aircraft gas turbines having a plurality -of combustion'chambers for :a single turbine, thistunequal '.fuel delivery lead to'ineiciency `andpossible-damagefand harmful' effect to the engine. f

The present invention ftherefore contemplates the ;p'rovision ofa variable area fuelfinjec'tion nozzle which can be .so `'adjusted tota selected :relationship of` flow to'epres sure 'that when a plurality of nozzles embodyingmyinvention, are conncctedto acommon .line having a selected .supply pressure, the rates `of fuelow of each nozzle will .be .known and will be identical with that of each other t nozzle within somepractical limit. v

To putit lanother way, each nozzle may be individually adjusted to meet a condition to which itis subjected so that fuel yis delivered by'that nozzle at the same or other `selected rate of vilow asis delivered by any other `nozzle in the assembly. 4 I n These, other and further advantages'and objects 'of the present invention will be clear .from the 'description 'which .follows and the drawings rappended thereto, 'in which Fig 'l vis a schematic Aplan view of an intrnal'combustion engine .such as a .gas turbine having a pluralit'yof combustion chambers to each of which 'a variable varea fuel injection nozzle embodying my inventio'nis applied. Fig. 2 is a longitudinal section through a'n injection nozzle embodying my invention and mounted "'on' a oom- Fig. I5 .is a partial view illustrating the spindle valve in closed position. Y

Fig. 6 is a viewsimila-r to Fig. 5 but showing the spindle valve in open position.

Fig. 7-is Ya-.par-tial view of Fig. v2 and showing thescrew stemin one adjusted .position Fig. 8 is a view similar to Fig. 7 and showing the screw stem-in another adjusted position.

Fig. :9 is a plurality of fcurves each showingrthe relationship of the inlet pressure -to the rate of .iluid 4flow -obtained `withan injection nozzle.

Fig. 10 is a longitudinal section of a modified form of an injection nozzleembodying'my inventionand mounted on a combustion chamber, shown in partial section.

Fig. l1 is a cross section von the line k11-11 of Fig. 10.

Fig. 12 is a ypartial view of Fig. 10 and showing the -valvein one adjusted position.

Fig. l13 is -a view similar to `Fig. 12 and showing the valve inlanother adjusted position.

Referring now to the ydrawings and more particularly to Figs. l to 5 incl., an vinternal combustion engine 10, `shown in schematic outline, is provided ywith a plurality of internal combustion chambers 12 to each of which -is connected to a fuel nozzle 14, shown in detail in Fig. 2.

-A :fuel ynozzle A14, embodying my invention may be mounted vas by threading it into a combustion chamber 11-2 of the `internal combustion engine 10 so that the tip portion or head 16 of the nozzle 14, through which the fuelisejected, extends in'to the fuel chamber the vselected distance.

The 'upper part -of the vtip portion or head 16 of the nozzle 14 Ibelow 'the ange 18 is preferably threaded at 20 so .that it may be screwed into corresponding internal threads of a combustion chamber. The entrance 22 to -an injection nozzle'according to amy invention is internally 'threaded so that it may be secured to a common line :running from a conventional mechanism for controlling the rate of fluid flow to the `combustion chambers 12, 'which mechanism, since it forms no part ofthe present invention and is conventional, need not be illustrated. Such fluid control mechanism may be in the. form of a centrifugal governor, a `manually controlled throttle or any number of other well known mechanisms.

The entrance 22 to m'y nozzle is formed in the cupshaped cover `2&1 which is screwed on the threaded collar 26-eXtending 'up from the ilange 1S and tightened thereon against a soft me'tal sealing Washer 28, which prevents external leakage.

The fuel vflows through the entrance l22 into the interior chamber 30 of the cover 24.

Threaded into the upper 'hollow tip portion or head 16, I provide Vthe stem portion 32.

Threaded on the outside of the stem piece 32, we provide the member 34, on which is mounted the 'adjusting 'screw'head 36.

The fuel Hows from lthe chamber 30 through the openings 38 inthe member 34, which are preferably spaced equally and 'radially 'thereaboug into the interior'chamfb`erv'40, through which the conical spindle 42 extends axially thereof.

The orifice plate 44 -is mounted at the head ofthe hollow Vstern portion for' member Thus axial 'adjustment lor positioning of the spindle 42 correspondingly changes 'and adjusts the area of the openings in the Sorifice 'plate 44 through which the fuel ows from the interior chamber *40 in fthe `member V34 -i'nto 'the Acorinnunicatin'g interior chamber 46 at the head Vof lthesten portion orfmember 32.

'Bychangingthe'ow area of etheforice in the vp1ate"44 (which is dependent upon the position "of the cone 48, las'viewediinlFigz, withmovernent'tothe lettering. 2 decreasing 'the 'area alniovement to Ithefrightt 'of Fig. `V'2i-n- 3 t creasing the area), the pressure drop across the orifice at a constant rate of ow is correspondingly changed,

The axial position of the spindle 42 and the relative position of `its cone-like head 48 tothe opening in the orificey plate 44 (and thus the size of the opening through which the fuel flows) may be selectively adjusted bymeans of the screw head 36 and the lock nut 50. v

The fluid is directed from the chamber 46 in the interior of the hollow stem member 32 into the interior of the tip portion or head 16 against the` outwardly llangedvalve head 52 on the pintle 54 and integral therewith.

The fluid pressure produces a force which tends to move the pintle 54 outward, that is to the right as viewed in Fig. 2, and open the valve.

The force on the valve head 52, which tends to` open the valve, is resisted by the spring 56.

In the prior art, the fluid pressure and spring force balance out at a selected point permitting the liuid to escape around the pintle 54 into the combustion chamber 12.

However, inithe valve embodying my invention, the force of the spring 56 is made adjustable, one means of accomplishing which adjustment will now be described.

In one form therefore, to adjust the tension of the spring 56, one end thereof is mounted on the rod 58, which latter is `supported by the pin 60 and trunnion 62 which trunnion engages a shoulder 64 in the interior of the stem portion or member 32.

The position of the stem portion or member 32 in the collar 26 of the tip portion or head 16 of my valve may be selectively adjusted by means of the lock nut 66 and the cooperating threads 68 on the stem portion 32 and the collar 26.

The tension of the spring 56 may thus be selectively changed, the pin 60 and the trunnion 62 preventing twist-` ing of the spring as the stern piece is rotated for adjust- I.

ment. The other end of the spring 56 is of course secured to the pintle 54 in the hollow interior 70 of the tip portion or head 16.

It will now be seen that I have provided a fuel injection valve which has two adjustments, namely, an orifice area adjustment and a tension adjustment of the spring which controls the opening of the valve.

Both of these adjustments affect the fuel` pressure at the valve inlet 22 which is required to maintain a given rate of fuel flow from the valve.

The elect, however, of the two adjustments are different in the operation of the valve.

Changing the tension of the spring 56 causes an approximately equal increase in the pressure required at any rate of flow of the fuel, while a change in the orifice area. at the plate 44, has a disproportionately large effect on the pressure at high rates of fuel ow but has `comparatively little effect on the pressure required at a low rate of fuel ow.

This difference in the effects of the two adjustments makes it possible to accurately achieve the desired performance at two dilerent points on a pressure against flow curve.

This is seen by a consideration of the curves illustrated in Fig. 9 to which reference is now made and which represents the llow rate at dilferent inlet pressures.

In this curve, the line AB represents the desired performance from the lirst group of nozzles. On a lirst test, a particular nozzle of this group may perform along the line CD. Reducing the `spring tension by selectively threading in the stem portion or member 32, the pressure required for a given flow would be reduced and the valve might be expected to perform along the line EF of Fig. 9.

Should the spring adjustment be made toproduce the desired operation `at a low rate, as illustrated, the pressure at high rates of ow may be lower than desired to obtain the required performance.

The orifice area may then be adjusted by means of the conical spindle 42 until the nozzle performance is that det 4 sired at high flow rates and thereby produce an operating curve such as that shown on the line AB of Fig. 9.`

Thus, proper adjustment of both the orice area and the spring tension will be seen to produce a rapid convergence to the desired operation. Thus, injection valves embodying my invention produce proper and desired performance at both high and low inlet pressures.

A nozzle embodying my invention may thus be used to meter the equal distribution of fuel among several combustion chambers as well as provide the sprayed or atomized injection of the fuel thereinto and at the same time is capable of adjustment to provide a pre-selected relationship between fuel inlet pressure and the rate of fuel ow.

The same resultsand purposes may be accomplished by other embodiments of my invention, one of which is illustrated in Fig. 10, to which reference will now be made. Lilie reference characters will be used to designate like parts.

It has been established in engineering practice that the rate at which the force of a spring increases with deflection, which is referred to as the sprngs rate, is inversely proportional to the number of active coils in the spring.

It will be apparent that any coil which is firmly gripped by a rigid member such as the rod 72 or the pintle 74 on which the valve head 76 is formed is not active.

Therefore, in Fig. 10 I have shown a means for actively engaging a greater or lesser number of spring coils.

The inner end of the stem portion 78 is threaded into the collar 26 and held there by the lock nut 66. The upper end 80 of the stem portion 78 is recessed to receive the trunnion 62, which is held against the shoulder 64. The rod 72 is held to the trunnion by means of the pin 60 and its threaded end 82 receives one end of the spring 56. Pin 60 acts against force of spring 56 and pin 60 rests against trunnion 62. This arrangement allows rod 72 to rotate.

The pintle 74 is threaded and receives the other end of the spring 56, the valve head 76 being inwardly recessed at 84 to receive and adjusting screw driver.

Thus, different coils of the spring may be engaged by the rod 72 at the upper end of the spring, that is to the left of Fig. l0 and different coils by the pintle 74, that is to the right of Fig. 10. Thus the spring rate may be selectively adjusted by rendering inactive different numbers of coils at each end of the spring 56.

In the type of assembly illustrated in Fig.` 10 the difference between the pressures required for low and for high fuel flows is determined solely by the change in the force exerted by the spring as itextends to accommodate the higher flows. Hence the effect of changing the spring rate is the same as the effect of changing the orifice area in the unit illustrated in Fig. 2 and the same adjustment may be achieved. Adjustment of the spring tension by means of 80 remains as in Fig. 2.

It will now be apparent that I have provided a fuel injection nozzle which can be adjusted to have the same performance as that of any other valve of this type and which valve performs as desired at both high and low inlet pressures to thereby equally distribute the fuel among several combustion chambers.

While I have shown and described certain sepecific examples of my invention, it will be understood that such examples are illustrative only and are not given as limitations, since other modifications within the spirit and scope of the invention will be apparent to those skilled in the art.

Hence, I do not intend to limit myself thereto but intend to claim my invention as broadly as may be permitted by the state of the prior art and the terms of the appended claims.

I claim:

1. In a fuel injection valve, a body having a hollow interior, an entrance to the interior of the body, a hollow tip portion threaded to the body, a hollow stem threaded to the tip portion and connecting the hollow interior of the body to the hollow interior of the tip portion, a valve head for opening and closing the tip portion, a threaded element extending from the valve head into the interior of the tip portion, a trunnion xedly held in the stem, a threaded rod extending from the trunnion into the stem and a coiled spring threaded at one end on the rod and at other end on the threaded element, said valve opened by the pressure of the fuel discharged from the valve against the valve head in opposition to the tension of the spring, said rod and said element being adjustably threaded into the coil spring to engage a seselected coil at each end of the spring to thereby adjust the spring rate whereby the ow of fuel from the valve is determined by the force exerted by the spring.

2. A fuel injection valve comprising a tubular nozzle spray tip formed with a valve opening at its outer end providing a valve seat, a valve head at said seat to close said opening, a tubular member screwed to the rear end of the nozzle tip, said tubular member being formed with an internal shoulder, a spider contacting said shoulder, said spider and said valve head being formed with stems projecting toward each other, a coil tension spring interconnecting said stems, one of said stems comprising a screw adapted to threadedly engage one end of said spring so that rotation of the stem will vary the number of active coils in said spring.

3. A fuel injection valve comprising a vtubular nozzle spray tip formed with a valve opening at its outer end providing a valve seat, a valve head at said seat to close said opening, a tubular member screwed to the rear end of the nozzle tip, said tubular member being formed with an internal shoulder, a spider contacting said shoulder, said spider and said valve head being formed with stems projecting toward each other, a coil tension spring interconnecting said stems, one of said stems comprising a screw adapted to threadedly engage one end of said spring so that rotation of the stem will vary the number of active coils in said spring, a hollow body attached to the rear end of the nozzle tip and enclosing the rear end of said tubular member, and said body being formed with an inlet opening.

References Cited in the ile of this patent UNITED STATES PATENTS 2,041,050 Cunningham May 19, 1936 2,452,283 Ball Oct. 26, 1948 2,555,803 Mashinter June 5, 1951 FOREIGN PATENTS 504,875 Great Britain May 2, 1939 909,177 France Dec. 10, 1945 

